acute

acute — adjective

1. causing very serious difficulty and needing fast action because the harm is alre

1.adjectiveC1
Definition

causing very serious difficulty and needing fast action because the harm is already great or getting worse.

Example

The town faced an acute water shortage after three weeks without rain.

acute shortage of + noun

Doctors warned of an acute lack of beds after the factory fire.

acute lack of + noun

Common collocations
  • acute shortage
  • acute lack
  • acute crisis
  • acute pressure
  • acute need
  • acute danger
Synonyms
  • severe

    close in meaning, but less strongly linked to urgency

  • critical

    stresses a danger point where immediate action may decide the result

  • grave

    more formal and often used for very bad news or risks

  • pressing

    focuses on urgency more than on damage already caused

Antonyms
  • minor

    describes something small and not very serious

  • manageable

    suggests the problem can be handled without major difficulty

Grammar Patterns

acute + problem/situation/shortage

be in acute need of + noun

acute lack/shortage of + noun

Usage Note

Usually modifies nouns such as shortage, need, danger, crisis, and pressure. Distinguish this sense from adjective/2: this one describes a serious situation, not a health problem or physical pain.

Common Mistakes

We had an acute picnic problem because the cake was small.
The camp faced an acute food shortage after the truck broke down.
Use this sense for major problems, not small inconveniences.

2. appearing suddenly and becoming very painful or dangerous within a short time, e

2.adjectiveC1
Definition

appearing suddenly and becoming very painful or dangerous within a short time, especially of illness or physical pain.

Example

Nina went to the hospital with acute chest pain after lunch.

acute + pain noun

The doctor treated an acute ear infection before it spread deeper.

acute + illness noun

Common collocations
  • acute pain
  • acute illness
  • acute infection
  • acute asthma
  • acute symptoms
  • acute attack
Synonyms
  • sharp

    often used especially for pain; less medical in tone

  • severe

    broader and does not by itself suggest sudden onset

  • sudden

    emphasizes speed of onset, not how serious the condition becomes

Antonyms
  • chronic

    medical opposite for long-lasting conditions

  • mild

    describes symptoms that are not strong or dangerous

Grammar Patterns

acute + pain/illness/infection

acute pain in + body part

acute + medical condition

Usage Note

Mostly used in medical contexts and often placed before pain or illness nouns. Frequently contrasted with chronic, which describes conditions that last a long time instead of starting suddenly.

Common Mistakes

My acute back problem has lasted for ten years.
My chronic back problem has lasted for ten years.
'acute' usually describes a sudden, short, severe condition, unlike 'chronic'.

3. quick and exact at noticing fine detail or understanding what is happening; used

3.adjectiveC1
Definition

quick and exact at noticing fine detail or understanding what is happening; used about the mind, senses, or observation.

Example

With her acute hearing, Mei noticed the weak alarm first.

acute + sense noun

The detective's acute eye spotted a missing button on the floor.

acute eye

Common collocations
  • acute mind
  • acute eye
  • acute ear
  • acute hearing
  • acute awareness
  • acute observation
Synonyms
  • keen

    very close in meaning and common with senses or intelligence

  • sharp

    more everyday; often used for minds and eyes

  • perceptive

    focuses on understanding hidden details or other people's feelings

  • observant

    stresses careful noticing more than quick intelligence

Antonyms
  • dull

    not quick at noticing or understanding

  • unobservant

    fails to notice details

Grammar Patterns

acute + mind/eye/ear/sense

acute awareness of + noun

acute comment/observation

Usage Note

Common with nouns like mind, eye, ear, sense, and awareness. Unlike adjective/1 and adjective/2, this sense is positive and describes skill in noticing or understanding small differences.

Common Mistakes

The camera is acute, so it takes clear photos.
The camera is sharp, so it takes clear photos.
This sense usually describes people, senses, or mental abilities, not machines.

4. describing an angle that opens less than ninety degrees.

4.adjectiveB2
Definition

describing an angle that opens less than ninety degrees.

Example

Each triangle in the pattern has two acute angles.

acute angles

Draw an acute angle at the top of the roof shape.

acute angle

Common collocations
  • acute angle
  • acute triangle
  • acute corner
Synonyms
  • narrow

    a plain-language description, not a technical geometry term

  • sharp

    informal description of how the angle looks

Antonyms
  • obtuse

    describes an angle greater than 90 degrees and less than 180

  • right

    describes an angle of exactly 90 degrees

Grammar Patterns

acute angle

angle is acute

Usage Note

Used almost only in geometry. It usually appears with angle or after be when naming the size of an angle, and it contrasts with right and obtuse.

Common Mistakes

A 120-degree angle is acute.
A 120-degree angle is obtuse.
Acute angles are below 90 degrees.

acute — noun

Word family

  • acutely
    adverbC1
  • acuteness
    nounC2
  • acuity
    nounC2

Synonym discussion

Sense: adjective/1

These words all describe serious problems, but they do not point to exactly the same thing. 'Acute' combines seriousness with urgency: it suggests a problem is already hurting people and needs quick action, as in an acute housing shortage. 'Severe' is broader and can describe strong damage, pain, weather, or rules without the same idea of immediate response. 'Critical' often marks a turning point where the next action may decide the result. 'Grave' is more formal and often sounds weighty or solemn. 'Pressing' focuses mostly on urgency, even if the problem is not yet disastrous. Compare: 'The city faces an acute water crisis,' 'The storm caused severe damage,' 'The patient is in critical condition,' 'They discussed the grave risk of war,' and 'We have pressing financial problems.'

acute ↗severe ↗critical ↗grave ↗pressing

Etymology

LatinEnglish

The word came into English from Latin. Latin 'acutus' meant 'sharp' or 'pointed', and it was related to the verb 'acuere', meaning 'to sharpen'. That older idea of sharpness still helps explain the modern senses: an acute angle comes to a sharper opening than a right angle, acute pain feels sharp and strong, and an acute mind notices fine differences quickly. Over time, English also developed the figurative sense of something being sharply serious or urgent, as in an acute shortage or crisis.